Schneider CA1 - Improvements

Improvements

During production, the type was gradually improved, which caused further delays. From the 245th vehicle onwards an automatic starter was installed, as the original manual system did not allow for a sufficiently quick response to a changing battlefield situation. Also it was decided the design was too poorly protected. After the first use of British Mark I tanks on 15 September 1916, the Germans had begun to introduce antitank-weapons. One of the measures taken by them was the issuing of the Kerngeschoss or "K-bullet", an armour-piercing hardened steel core round. To defeat it, from the 210th vehicle onwards the Schneider tank was fitted with 5.4 millimetres spaced armour plates on the sides and front, with a distance of four centimetres between the main armour and the appliqué. Even without the spaced armour, the front plates would have been immune against K-bullet fire from a distance of two hundred metres, because of their 60° angling, providing an effective line-of-sight thickness of 22.8 millimetres. During the spring of 1917 existing vehicles were uparmoured (creating a surblindé version) by the army workshop at Champlieu. On 1 April 1917 of the 208 tanks available only about a hundred had been retrofitted. None of the older tanks had at this point yet received the new starter engine, this part of the improvement process would take until the end of the summer.

The first combat actions showed that the fuel reservoir was prone to explode when the vehicle was hit by an artillery round. To remedy this the reservoirs were replaced by fuel tanks with a double wall, using a felt filler layer to absorb gasoline leakages. Furthermore these fuel tanks, of eighty litres each, were moved to a safer position, under armour but outside the original hull, in vertical rectangular steel boxes to the left and right of the rear door. This necessitated the construction of an additional safer exit gate, at the left side of the vehicle. On 8 September 1917 only twelve tanks had been changed to this new configuration. On 21 March 1918 about 245 vehicles featured all three major improvements.

Numerous smaller modifications were introduced during the testing phase and the production run. The first included an improved cooling system and better ventilation to prevent and remove carbon monoxide fumes which otherwise threatened to asphyxiate the crew within an hour. To prevent dirt entering the chassis near the crank, at the bottom of the vehicle an armour plate was added. Later additions were a periscope sight, an exhaust pipe and speaking tubes for internal communications.

Some improvements were studied but eventually not applied. Simple ones included the introduction of track shoes with a chevron profile to improve grip. One vehicle, with series number 61213, was fitted with additional armour plates on the vertical front surfaces, including an extra rectangular shield around the gun barrel. Much more far-reaching were early proposals to fundamentally change the design, to be implemented during the production run. These were inspired by the awkward lay-out in which to limit the width of the tank, the main armament had been placed in an inconvenient position. On 1 December 1916 a certain Lieutenant Saar submitted drawings showing a vehicle on which the 75 mm cannon had been replaced by a 47 mm gun turret, the number of machine guns was raised to six, the number of vision slits to eleven and the engine was located in the middle of the hull. On 28 and 29 December 1916 the Schneider company considered to move the 75 mm gun to the nose of the vehicle and give it a 120° traverse. In 1917, to provide some modicum of communication with higher command levels, a hinged metal shield was attached to the rear of the hull skylight roof. Its back was painted in a conspicuous horizontal tricolour red-white-red scheme. When lifted by means of a steel cable operable from the inside via a grooved small vertical plate located on the front of the skylight roof, it indicated the position of the tank to friendly observers from behind.